1. Field of the Invention
The presented invention relates to computer add-on cards, particularly to a computer add-on card that is capable of outputting various different type of digital TV signals depending on user configuration.
2. Description of Related Art
Digital TV has recently become the focus of the next generation entertainment and information service in the broadcast environment. Many institutions and standard bodies have published different Digital TV standards with different signal formats (PECL, LVDS, RS-422, etc.) and interfaces (204-Byte parallel mode, serial, etc.) based on Motion Picture Experts Group-2 (MPEG-2) standard. Each Digital TV standard has its own application and market segment.
To cope with this situation, a testing toolxe2x80x94such as MPEG-2 Transport Stream generatorxe2x80x94with various signal format and interface support is an important key to the digital TV related products development. Conventionally, this kind of testing tool is very expensive and only provides some limited number of output formats. If user needs another output signal format and interface, he has to spend more money to purchase a signal converter or even a new module from the original manufacturer. In the worst case user will have to purchase it from another testing tools manufacturer if the original manufacturer does not support this signal format. Again because these testing tools are not compatible one another, user must purchase a whole new testing tool set from the other manufacturer and abandon the old one that has exactly the same functions except the different output signal and interface. From the user""s view point, it is quite a waste of resources. The more Digital TV standards they adopt in your products, the more waste they make to purchase these testing tools. Therefore, to improve this condition users need a low cost and easy to implement testing tool that is capable of outputting different signal formats and interfaces.
The main purpose of the presented invention is to provide a low cost PCI based add-on card that is capable of transmitting various Digital TV signal formats depending on user""s requirement. This add-on card comprises the following components:
An interface daughter board for converting the output signal format.
A Peripheral Component Interconnect (PCI) bus interface that connects to computer""s PCI slot.
A PCI Bridge to handle communication between computer host and this add-on card.
A Field Programmable Gate Array (FPGA) unit that provides control signal conversion.
A bit rate generator that produces all the clock signals needed by the system.
Two First In First Out (FIFO) buffers that function as temporary data storage.
An output connector where various DTV signal formats are output from.
Using this flexible design architecture, it is very easy to integrate any Digital TV signal formats and interfaces to this testing tool. To have different output interface, all the user needs to do is replacing the daughter board on this add-on card with the new different one and setting the appropriate control jumper position. The user does not need to change anything else, including the application program, and everything will work properly.